The Fibroblast Growth Factor (FGF)—Fibroblast Growth Factor Receptor (FGFR) signaling pathway is widely implicated in the development and maintenance of many different cancers. This signaling pathway comprises 4 different FGF receptors (FGFR1, FGFR2, FGFR3, and FGFR4), some of which are also alternatively spliced, and 22 different FGF ligands. Each FGF receptor and splice form has different patterns of expression and different specificities for the various FGF ligands.
FGFR1 is the best characterized of the four FGFRs. FGFR1 and its ligands have causal connections to cancer in animal models and strong correlative connections to human disease. Specific induction of FGFR1 signaling in mouse prostate results in prostate hyperplasia and carcinoma (Freeman et al., Cancer Res. 2003; 63:8256-63), demonstrating that abnormal hyperactivation of FGFR1 is sufficient to initiate tumorigenesis. Inhibition of FGFR1 activity inhibits tumor growth in xenograft models from multiple tissue types (Ogawa et al., Cancer Gene Ther. 2002; 9:633-40). In human disease, chromosomal amplification of the FGFR1 gene in a subset of breast cancer patients is associated with poor outcome (Gelsi-Boyer et al., Mol. Cancer. Res. 2005; 3:655-67) and overexpression or high systemic levels of FGF ligands correlate with tumorigenesis and poor patient outcome (Nguyen et al., J. Natl. Cancer Inst. 1994; 86:356-61).
FGFR1 has multiple mechanisms in the promotion of tumor cell growth and survival. FGFR1 signaling increases the mitotic rate of tumor cells, promotes tumor angiogenesis, and helps maintain the tumorigenicity of tumor stem cells (TSCs). Many tumor cell lines are responsive to and dependent on FGFR1 signaling for growth in vitro, and tumor cell lines become resistant to cytotoxic agents when stimulated with FGF-2 (Song et al., PNAS 2000; 97:8658-63). Disruption of the FGF-FGFR1 pathway leads to reduction of tumor cell growth in vitro and in xenografts (Ogawa et al., Cancer Gene Titer. 2002; 9:633-40). Specific inhibition of FGFR signaling may therefore cause reduction in the growth rate of human tumors.
Some FGFs have potent angiogenic activities and play important roles in tumor vasculogenesis (Compagni et al., Cancer Res. 2000; 60:7163-69). In murine models of pancreatic cancer, FGFs mediate escape from anti-vascular endothelial growth factor receptor (VEGFR) therapy. A similar phenomenon is seen in glioblastoma multiforme patients treated with anti-VEGFR therapy, in whom tumor progression correlates with greatly increased levels of FGF-2 (Batchelor et al., Cancer Cell 2006; 11:83-95). Inhibition of FGFR1 might reduce tumor angiogenesis, particularly in tumors previously treated with anti-VEGF therapies.
There is increasing evidence that tumors contain a small population of malignant cells (TSCs) that are phenotypically similar to stem cells that may be responsible for tumor initiation, survival, proliferation, and recurrence. These cells are dependent on the presence of FGFs to maintain their TSC phenotypes (Dvorak et al., FEBS Letters 2006; 580:2869-74). When FGFs are withdrawn from in vitro cultures of TSCs, they stop proliferating and appear to differentiate. Thus, inhibition of FGFR1 signaling may lead to reduced metastases and recurrence of tumors.
Soluble FGFR1 fusion proteins are able to bind to FGF ligands of the FGFR1 receptor, “trapping” the ligands and prevent them from activating FGFR1 receptors as well as other receptors for which the ligands have affinity. See, e.g., U.S. Pat. No. 7,678,890. Without being bound to a particular theory, it is believed that soluble FGFR 1 fusion proteins can inhibit tumorigenic activity through multiple mechanisms of action, including but not limited to, direct anti-tumor activity in cancers dependent on the FGF-FGFR pathway, inhibition of tumor angiogenesis, and/or inhibition of cancer stem cell maintenance.
The data provided here show for the first time that a soluble FGFR1/Fc fusion protein, FP-1039, can be administered safely to human patients at concentrations of about 2 mg/kg body weight or higher (i.e., up to at least about 16 mg/kg) and that such concentrations are well-tolerated. As shown in detail in the Examples, in some embodiments, treatment of humans with FP-1039 yields pharmacokinetic and pharmacodynamic profiles that indicate weekly or less frequent administration of doses above 2 mg/kg, 4 mg/kg, 8 mg/kg or 10 mg/kg is sufficient for sustained sequestration of target FGF ligands such as FGF-2.
In one aspect, the present invention provides methods of treating a human having a cancer. In some embodiments, the method comprises administering to the human a therapeutically effective amount of a soluble Fibroblast Growth Factor Receptor 1 (FGFR1) fusion protein, wherein the fusion protein comprises an extracellular domain of an FGFR1 polypeptide linked to a fusion partner. In some embodiments, FGFR1 fusion protein is administered at a dose of about 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 25, 26, 28 or 30 mg/kg body weight, or within a range from one to another of the above dose values (the above doses being calculated using an extinction coefficient of 1.42 mL/mg*cm). In some embodiments, the FGFR1 fusion protein is administered at a dose of about 10 mg/kg body weight as calculated using an extinction coefficient of 1.11 mL/mg*cm. In other embodiments, the FGFR1 fusion protein is administered at a dose of about 20 mg/kg body weight as calculated using an extinction coefficient of 1.11 mL/mg*cm, or at a range of about 10 to about 20 mg/kg body weight as calculated using an extinction coefficient of 1.11 mL/mg*cm. In some embodiments, the human has a fibroblast growth factor-2 (FGF-2) plasma concentration of at least 6 pg/ml. In some embodiments, the cancer is characterized by a ligand-dependent activating mutation in FGFR2. In some embodiments, the ligand-dependent activating mutation in FGFR2 is S252W or P253R. In some embodiments, the soluble FGFR1 fusion protein is administered in combination with a chemotherapeutic agent or a VEGF antagonist.
In some embodiments, the FGFR1 polypeptide is human FGFR1 isoform IIIc. In some embodiments, the fusion partner is an Fc polypeptide, which is the Fc region of human immunoglobulin G1 (IgG1). In some embodiments, the FGFR1 extracellular domain has the amino acid sequence of SEQ ID NO:5. In some embodiments, the soluble FGFR1 fusion protein has the amino acid sequence of SEQ ID NO:8.
In some embodiments, the soluble FGFR1 fusion protein is administered at a dose of about 2 mg/kg body weight to about 30 mg/kg body weight. In some embodiments, the soluble FGFR1 fusion protein is administered at a dose of about 8 mg/kg body weight to about 16 mg/kg body weight (or about 10 mg/kg body weight to about 20 mg/kg body weight when calculated using an extinction coefficient of 1.11 mL/mg*cm). In some embodiments, the soluble FGFR1 fusion protein is administered at a dose of about 8 mg/kg body weight, while in some embodiments, the soluble FGFR1 fusion protein is administered at a dose of about 16 mg/kg body weight (or at about 10 mg/kg body weight or about 20 mg/kg body weight, respectively, when calculated using an extinction coefficient of 1.11 mL/mg*cm).
In some embodiments, the method comprises administering FP-1039 to a human patient having cancer, wherein the human has a fibroblast growth factor-2 (FGF-2) plasma concentration of at least 6 pg/ml and wherein FP-1039 is administered at a dose of about 2 mg/kg to about 30 mg/kg. In some embodiments, the soluble FGFR1 fusion protein is administered at a dose of about 8 mg/kg body weight. In some embodiments, the FP-1039 is administered at about 16 mg/kg.
In some embodiments, the soluble FGFR1 fusion protein is administered twice a week, weekly, every other week, at a frequency between weekly and every other week, every three weeks, every four weeks, or every month.
In some embodiments, the soluble FGFR1 fusion protein is administered intravenously or subcutaneously.
In some embodiments, the cancer is prostate cancer, breast cancer, colorectal cancer, lung cancer, endometrial cancer, head and neck cancer, laryngeal cancer, liver cancer, renal cancer, glioblastoma, or pancreatic cancer.
In some embodiments, the human has an FGF-2 plasma concentration of at least 10 pg/ml prior to the administration of the soluble FGFR1 fusion protein. In some embodiments, the soluble FGFR1 fusion protein is administered at a dose such that at seven days after administration, the human has an FGF-2 plasma concentration of less than 4 pg/ml.
In some embodiments, the soluble FGFR1 fusion protein is administered in combination with a chemotherapeutic agent. In some embodiments, the chemotherapeutic agent is sorafenib. In some embodiments, the soluble FGFR1 fusion protein is administered in combination with a VEGF antagonist. In some embodiments, the VEGF antagonist is a VEGF antibody, such as bevacizumab, or the VEGF antagonist is a VEGF trap, such as aflibercept. In some embodiments, the soluble FGFR1 fusion protein is administered in combination with an anti-angiogenic agent.
The present invention also provides for methods of treating a human having a cancer, wherein the cancer is characterized by an Fibroblast Growth Factor Receptor 2 (FGFR2) having a ligand-dependent activating mutation, the method comprising: administering to the human a soluble Fibroblast Growth Factor Receptor 1 (FGFR1) fusion protein at a dose of about 2 mg/kg body weight to about 30 mg/kg body weight, wherein the fusion protein comprises an extracellular domain of an FGFR1 polypeptide linked to a Fc polypeptide. In some embodiments, the soluble FGFR1 fusion protein is administered at a dose of about 8 mg/kg body weight, while in some embodiments, the FP-1039 is administered at about 16 mg/kg body weight (or about 10 mg/kg body weight or about 20 mg/kg body weight, respectively when calculated using an extinction coefficient of 1.11 mL/mg*cm).
In some embodiments wherein the cancer is characterized by an FGFR2 having a ligand-dependent activating mutation, the FGFR1 polypeptide is human FGFR1 isoform IIIc. In some embodiments wherein the cancer is characterized by an FGFR2 having a ligand-dependent activating mutation, the Fc polypeptide is an Fc region of human immunoglobulin G1 (IgG1).
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the FGFR 1 extracellular domain comprises the amino acid sequence of SEQ ID NO:5. In some embodiments, the soluble FGFR1 fusion protein comprises the amino acid sequence of SEQ ID NO:8.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered at a dose of about 2 mg/kg body weight to about 30 mg/kg body weight. In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered at a dose of about 8 mg/kg body weight to about 16 mg/kg body weight (or about 10 mg/kg body weight to about 20 mg/kg body weight when calculated using an extinction coefficient of 1.11 mL/mg*cm). In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered at a dose of about 8 mg/kg body weight, while in some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered at a dose of about 16 mg/kg body weight (or about 10 mg/kg body weight or about 20 mg/kg body weight, respectively when calculated using an extinction coefficient of 1.11 mL/mg*cm). In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the FGFR1 fusion protein is administered at a dose of about 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 25, 26, 28 or 30 mg/kg body weight, or within a range from one to another of the above dose values. In some embodiments, dosages may be administered weekly, every other week, at a frequency between weekly and every other week, every three weeks, every four weeks, or every month.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the method comprises administering FP-1039 to a human patient having cancer, wherein the cancer is characterized by an FGFR2 having a ligand-dependent activating mutation, and wherein FP-1039 is administered at a dose of about 2 mg/kg to about 30 mg/kg. In some embodiments, the FP-1039 is administered at about 8 mg/kg, while in some embodiments, the FP-1039 is administered at about 16 mg/kg (or about 10 mg/kg body weight to about 20 mg/kg body weight when calculated using an extinction coefficient of 1.11 mL/mg*cm).
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered weekly or every other week or a frequency between weekly and every other week.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered intravenously or subcutaneously.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the cancer is prostate cancer, breast cancer, colorectal cancer, lung cancer, endometrial cancer, head and neck cancer, laryngeal cancer, liver cancer, renal cancer, glioblastoma, or pancreatic cancer.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the human has an FGF-2 plasma concentration of at least 10 pg/ml prior to the administration of the soluble FGFR1 fusion protein. In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered at a dose such that at seven days after administration, the human has an FGF-2 plasma concentration of less than 4 pg/ml.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered in combination with a chemotherapeutic agent. In some embodiments, the chemotherapeutic agent is sorafenib. In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the soluble FGFR1 fusion protein is administered in combination with a chemotherapeutic agent, VEGF antagonist or anti-angiogenic agent. In some embodiments, the VEGF antagonist is a VEGF antibody, such as bevacizumab, or the VEGF antagonist is a VEGF trap, such as aflibercept. In some embodiments, the soluble FGFR1 fusion protein is administered in combination with an anti-angiogenic agent.
In some embodiments for treating cancer characterized by an FGFR2 having a ligand-dependent activating mutation, the ligand-dependent activating mutation in FGFR2 is S252W or P253R.
The present invention also provides a composition comprising a soluble FGFR1 fusion protein for use in the treatment of cancer, wherein the composition is administered at a dose of at least about 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 25, 26, 28 or 30 mg/kg body weight, or within a range from one to another of the above dose values. In some embodiments, dosages may be administered twice a week, weekly, every other week, at a frequency between weekly and every other week, every three weeks, every four weeks, or every month. In some embodiments, the human has a fibroblast growth factor-2 (FGF-2) plasma concentration of at least 6 pg/ml. In some embodiments, the cancer is characterized by a ligand-dependent activating mutation in FGFR2. In some embodiments, the ligand-dependent activating mutation in FGFR2 is S252W or P253R. In some embodiments, the soluble FGFR1 fusion protein is administered in combination with a chemotherapeutic agent or a VEGF antagonist.
Any embodiment described herein or any combination thereof applies to any and all methods of the invention described herein.